The finding that succinic dehydrogenase does not occur in any mitochondria of the retina between the outer limiting membrane and the layer of optic nerve fibers is not new. Many biochemists have had the dictum that succinic dehydrogenase is the backbone of mitochondria, thus we have gone to some trouble to show its absence in all retinal elements but the ellipsoids and paraboloids. We are not the first to demonstrate the cholinergic nature of optic nerve endings in tectum, but it was necessary to do this exhaustively. It is not obvious that curare should affect vision, but in the frog it does change significantly the activity of tectal cells in response to visual stimuli. We have developed a sensitive, reliable and repeatable method for using the long time concentrations to "fingerprinting" CNS drugs in concentrations at which they are effective. The development of a sensitive, nontouching method for detecting certain spherical aberrations in human eyes that are not easily found otherwise is to have the patient straighten out a seen grid by moving two knobs. This method classifies the aberration, specifies whether it is correctable and determines the sort of correction needed. The production of an understandable and graphic model of the teledendron as a shaped filter in the time domain often escapes understanding when it is presented. A computer model of the process has been coupled to a graphics output and filmed so as to show the types of transform that can be found with codes such as are recorded in frog optic nerve. The demonstration of recording from the cells of laminae 2 and 3 in the substantia gelatinosa of the spinal cord of the cat is, we think, the first time such activity has been recorded. The cells encode a mixture of the ordinary affections of skin senses together with nocioceptive and temperature information.